I have a fake calculator which has no solar panel (just a piece of plastic made to look like one) no battery in the compartment, (no contacts either), the battery is actually inside the case on the circuit board.The QR code takes me to a random page on the Casio website not the authentication page. However it does show "Casio" in the display when turned off and it does have Casio printed on the case and the back so I don't think those two checks are valid. However mine also says use battery "AAA" which is clearly insane whereas yours says use LR44 which seems correct. I assume there are just lots of fakes out there so each has its own issues.
Hmmm is that a fake? I don't seem to see a warranty sticker Also the qr code you just showed will take you to the website containing the info that you just put on the calculator. The way to test is for the sticker and by pressing menu then shift Optn-QR.if the code didn't work or leads to the wrong page other than the authenticity check that means it's not real. Also you can do this by pressing shift,menu,scroll to the bottom,select qr code, select version 3,then press enter,then ac,then go press menu,then spreadsheet,put anything on it,then press qr,if it works then nost likely fake. If it doesn't, shows not supported version 3... That means it's real😅
Engineering student here 👋. I Switched from Casio 991 Es to 991 Ex Classwiz in high school for easier unit conversion, matrix calculations, equation solving, and data tabulation. Convenient screen display but stiff buttons make long study sessions overwhelming.